NUnit和Visual Studio 2008的单元测试的测试项目?

I am going to be starting up a new project at work and want to get into unit testing. We will be using VS 2008, C#, and the ASP.NET MVC stuff. I am looking at using either NUnit or the built in test projects that VS2008 has, but I am open to researching other suggestions. Is one system better than the other or perhaps easier to use/understand than the other? I am looking to get this project set up as kind of the "best practice" for our development efforts going forward.I am going to be starting up a new project at w